Sand all surfaces lightly with fine grit sandpaper. Do not use steel wool as it tends to shed fibres that stick to the grain and ruin a smooth finish. Stain all surfaces of the register: top, ends and louvers to the desired color. No need to finish the back of the vent as it is sealed at the factory.
1. Allow to dry thoroughly.
2. Apply three coats of desired finish to all surfaces with a light sanding in between.
3. Allow to dry thoroughly